Drawing-com pass



(No Model.)

A. KVOROSS.

DRAWING OOMPASSBS. 5 No. 555,803. Patented Mar. 3, 1896.

A REW EGRAHAM. FIIOTOLIYNQWASHIN GTOILD C FFlCEE.

ATENT ANSON K. CROSS, ()F BOSTON, MASSACHUSETTS.

DRAWING-COMPASS.

SPECIFICATION formingvpart of Letters Patent No. 555,803, dated March 3, 1896. Application filed November 30,1894. Serial No. 530,332. (No model.)

To aZZ whom it may concern:

Be it known that I, ANSON K. CROSS, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Drawing-Instruments; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates more directly to the main joint and to the needle-point for dividers or compasses.

The object of the invention is to provide drawing-compasses with a reliable adjustable joint in which the wear may be taken up, and comprising also a simple and effectual needle-point and which will be capable of manufacture at such a low price as to be within the reach of all, including public-school children.

The invention will be fully set forth in the following specification and claims, and clearly illustated in the drawings accompanying and forming a part of same, of which Figure 1 is an elevation of a pair of my improved compasses as when partly opened,

' Fig. 2 being a vertical section taken at 2 2,

Fig. 1. Fig. 3 is adetail in perspective show ing the spring-expander. Fig. 4 is an enlarged broken section showing the socket for the needle-point. Figs. 5 and 6 show slight modifications in the joint, and Fig. 7 is a vertical section of socket containing the needle.

Similar letters designate corresponding parts.

Ais the pencil-point leg, which is provided at its top with cars a, perforated for the reception of the rivet S. The leg B has at its top two perforated ears I), which are formed thin enough to be slightly yielding.

In order to carry out my invention it is desirable that the ears I) shall be capable of being forced or spread apart outwardly against the inner sides of the cars a in order that the joint composed of the cars a and b and the rivet S may be sui'liciently tight at all times, regardless of possible wear. Hence I provide an adjustable expander composed of a suitable spring, which may be of helical form and placed upon the rivet S, between the ears I) of the legs B; but I consider a separator or expander, such as shown at C, preferable, which consists of a Wedge-shaped spring having its sides perforated for the entrance of the rivet S and curved, as at c, to afford a more even bearing-surface against the ears I).

The upper ends of the spring 0 slope away from each other, as at c, and one end extends above the other and may be increased in thickness and bent, as shown at D, or the said part D may be attached, if preferred; and this part D will carry an adjusting-screw E, which is adapted to bear between and against the sloping sides 0 of the spring 0, and thus regulate the pressure of the ears 1) against the cars a for tightening the joint as desired.

To prevent the adj Listing-screw E from working loose, a suitable set-screw 61 may be threaded through the side of said part D, and bearing against the screw E hold the latter wherever it is set.

The lower portion of the leg B terminates in i atube I), which is preferably slotted, as shown at W, for a distance nearly equal to the length of the needle-point F, which is adapted to fit therein, its upper end resting against a shoulder which prevents it from working up too far in the tube, the natural spring of the tube being all suiiic'ient to retain said needle-point in its proper position; and if constructed as seen in Fig. 7 the needle F may be a broken piece of an ordinary sewing-needle, the bot tom of the socket b forming its shoulder, in place of the more expensive method of forming it upon the needle.

The modification shown in Figs. 5 and 6 introduces washers T, which are placed one between each side of the expander O and the ears I), thus permitting said expander or spring 0 to revolve without causing motion of the legs.

I am aware that the axis of calipers has been surrounded with a coil-spring connected to the caliper members in manner to open them, the extent of their separation or opening being made regulable by a screw, and also that a compass-joint has been formed by conical ears integral with the members and adapted to closely embrace each other, the inner ears being made to act as springs, and such devices are not of my invention.

\Vhat I claim is 1. In dividers or the like having two members or limbs pivotally connected, the approximately V-shaped spring having the point formed by the junction of its two members and also the main body of said members situated below the pivot and between the limbs of the dividers, and the pivot passing through the two limbs of the spring, said spring extending above the joint of the dividers to form a head, substantially as described.

2. In dividers or the like having two members, each member provided with two ears integral therewith, such as a and b, a separate regulable spring situated between the ears of one member and pressing them out wardly against the corresponding ears of the other member, and a pivot passing through said ears and through the, spring, substantially as set forth.

3. In dividers or the like having two members, a separate regulable spring situated between the jointed ends of said members and a pivot passing through said ends and through the spring, and a screw bearing on the spring to expand the same against said members, substantially as set forth.

4:. In dividers or the like having two members, a spring situated between the jointed ends of said members and a pivot passing through said ends and through the spring, and a screw to expand the spring against said member, and a nut D fixed to said spring to receive the screw and hold it in operative relation to the spring, substantially as set forth.

5. In dividers or the like and in combination with its two members a spring C provided with two limbs having together a wedge form, a nut D fixed on one limb, and a screw movable through the nut and between the said limbs and a pivot connecting the divider members and spring, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

ANSON K. GROSS.

Witnesses:

JUsTIN II. SMITH, M. E. NoYEs. 

